CanvasChamp.com has Custom 18" x 24" Canvas Photo Print (Includes Wrap, Backing, Hardware) on sale for $12 when you enter discount code ONE22X18CC at checkout. Shipping is $9.99.
Note, be sure to select the Custom Size (H x W) of 18" x 24" on the product page. You may also purchase more for additional savings:
Two 18" x 24" for $23.10 ($11.55 Each) w/ discount code: TWO22X18CC
Three 18" x 24" for $34.1 ($11.37 Each )w/ discount code: THREE22X18CC